In short: A mill test certificate 3.1 – in the standard's own words an inspection certificate 3.1 according to EN 10204 – is the manufacturer's proof that the delivered batch meets the ordered product standard: with the chemical composition and the mechanical test results per heat, validated by an authorised inspection representative independent of the manufacturing department. Anyone who buys steel, castings, forgings or pipes receives one with every delivery. Tiro reads such certificates from PDFs and scans and returns them as a table – in the example 13 header fields and 5 heats with 15 values each from two separate tables, merged into one row per heat.
Below is the complete example: the certificate, the extracted data and the result in the app.
The certificate types of EN 10204 compared
EN 10204 defines four types of inspection documents for metallic products. They differ in whether test results are included, what was tested and who signs:
| Type | Name | Test results | Validated by |
|---|---|---|---|
| 2.1 | Declaration of compliance with the order | none – only confirmation that the delivery complies with the order | manufacturer |
| 2.2 | Test report | results of non-specific inspection (not necessarily on the delivered batch) | manufacturer |
| 3.1 | Inspection certificate | results of specific inspection on the products delivered | manufacturer's authorised inspection representative, independent of the manufacturing department |
| 3.2 | Inspection certificate | as 3.1 | manufacturer's representative and the purchaser's authorised representative or an inspector designated by official regulations |
In purchasing, 3.1 is the default as soon as load-bearing, pressure-retaining or safety-relevant parts are involved: rules such as the Pressure Equipment Directive or EN 1090 usually require specific inspection with traceability to the heat for such materials. Which type has to be supplied is always defined by the purchase order.
What an inspection certificate 3.1 contains
The layout differs from mill to mill; the content follows the product standard and is therefore remarkably similar:
- Header: certificate number and type, manufacturer and works, purchaser, PO and delivery note number, product (e.g. heavy plate, pipe, bar), standard and grade (EN 10025-2, S355J2+N in the example), delivery condition (+N, +AR, +M …), dimensions and total weight.
- Identification per item: heat number (cast), plate/pipe/coil number, pieces, weight – the bridge between the certificate and the physical material in the yard.
- Chemical composition (heat analysis): mass fractions in % per heat – C, Si, Mn, P, S, for alloyed grades Cr, Ni, Mo, V, Nb …, often with the carbon equivalent CEV. Next to them the limits of the standard for comparison.
- Mechanical properties: tensile test with yield strength ReH, tensile strength Rm and elongation A; Charpy impact test with test temperature (−20 °C for J2) and impact energy KV2 as three individual values plus the average; depending on the product hardness, bend test, ultrasonic testing.
- Validation: statement that the products comply with the requirements of the order, name and signature of the inspection representative, date – with certificates via EDI or portal mostly digitally signed today.
Who receives certificates – and what has to happen with them
Whoever produces material writes certificates – whoever buys material from many suppliers receives them: incoming inspection, quality assurance and materials engineering at steel fabricators, valve and pressure equipment makers, shipyards, plant and machine builders. Every delivery brings a 3.1 – from every mill and stockholder in a different layout, often scanned or faxed. Before release the values per heat have to be recorded and checked against the standard and the company's own specification; afterwards they stay in the material database or the construction file for traceability. That retyping – and the transcription errors that come with it – is the work that can be automated.
Extracting certificates: from PDF to material table
A PDF-to-Excel converter copies the page layout into cells. For a mill certificate that means chemistry and mechanics stay two separate blocks, the specification limits land between the results, and the heat number has to be matched by hand. Tiro works with fields instead of layout: you define once which header fields and which columns per heat you need, and every certificate – whichever mill it comes from – runs into the same table. Numbers are normalised by default: 0.014 % phosphorus is a number, −20 °C is a signed number, and the printed average of the three impact values is taken as instructed. What comes out of Tiro, Excel can compare against your limits right away. The quality assurance page shows the same idea for laboratory reports and certificates of analysis; scanned or photographed certificates work as shown under PDFs & scans.
